An electrical isolation barrier (also referred to as a galvanic isolation barrier) is used to electrically isolate one electronic circuit from another electronic circuit. Two electronic circuits are considered to be electrically isolated when at most a threshold level of current flows in response to application of a voltage above a voltage threshold across any node of the first electronic circuit and any node of the second electronic circuit. In typical telecommunication applications, the current threshold is 10 milliamperes (mA) or less and the voltage threshold is 1000 volts (V) or more. Other applications, particularly those involving medical equipment impose much lower threshold current levels. Electrical isolation barriers are used in a wide variety of different applications, including separating measurement instruments from sensors operating in adverse environments, separating patients from high voltages present in measurement instruments, and separating circuitry that is connected directly to a residential power outlet from circuitry that is connected directly to the standard two-wire telephone network.
Data signals typically are communicated across an electrical isolation barrier using optical coupling, electrostatic coupling, or magnetic coupling. Acoustic coupling of data signals across large-scale ultrasonic coupling media such as the wall of an aircraft or rocket fuel tank have been proposed. The acoustic transducers that are used in these approaches are formed from bulk crystal resonators, which are large (e.g., 12.6 millimeters (mm) in diameter) and are limited to low-frequency and low-bandwidth applications (e.g., on the order of 1 Megahertz (MHz) or less). In addition, the manufacturing techniques that are used to fabricate such bulk crystal resonators typically cannot control the operating characteristics of these devices with tight tolerances
What is needed is a low-cost, compact electrical isolation approach that is capable of high-frequency, high-bandwidth data transmission and is capable of being manufactured with tight operating characteristics tolerances. It additionally would be desirable if such an approach could be used to supply sufficient electrical power to operate auxiliary electronic circuits and components on the isolated side of the electrical isolation barrier.